MacBook Pro Keyboard Backlight Not working

So, I got this MacBook from a friend, as he didn’t have a use for it anymore, it was originally a 2010 model but it got a logic board replacement, idk if that affects it. there were some problems with the RAM at first but its fixed now.

Anyway, I often do use the MacBook in low light and I normally can see the keyboard. So I use the backlight but to my surprise the thing doesn't work! It shows up as working on the OS (10.12.6) but nothing happens, I have tried it on other os's to see if it was a os problem but no luck.

I have checked the board for water damage, none.

Checked the connector in the board and the actual cable, both fine.

there haven't been any other problems with the MacBook otherwise I am just asking if it is a problem with the logic board or if its the backlight itself

Hope to hear from someone who can help

cheers ;)